| Message ID | 2e43e3a409b7fa5f4781e30f3d7b7e56aa5d1fb0.1314398066.git.udeshpan@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Sat, Aug 27, 2011 at 02:09:44PM -0400, Umesh Deshpande wrote: > Currently, when any thread other than iothread calls vm_stop, it is scheduled to > be executed later by the iothread. This patch allows the execution of vm_stop > from threads other than iothread. This is especially helpful when the migration is > moved into a separate thread. > > Signed-off-by: Umesh Deshpande <udeshpan@redhat.com> > --- > cpus.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/cpus.c b/cpus.c > index de70e02..f35f683 100644 > --- a/cpus.c > +++ b/cpus.c > @@ -122,8 +122,8 @@ static void do_vm_stop(int reason) > { > if (vm_running) { > cpu_disable_ticks(); > - vm_running = 0; > pause_all_vcpus(); > + vm_running = 0; > vm_state_notify(0, reason); > qemu_aio_flush(); > bdrv_flush_all(); Why this change?
On 08/29/2011 06:56 PM, Marcelo Tosatti wrote: >> > diff --git a/cpus.c b/cpus.c >> > index de70e02..f35f683 100644 >> > --- a/cpus.c >> > +++ b/cpus.c >> > @@ -122,8 +122,8 @@ static void do_vm_stop(int reason) >> > { >> > if (vm_running) { >> > cpu_disable_ticks(); >> > - vm_running = 0; >> > pause_all_vcpus(); >> > + vm_running = 0; >> > vm_state_notify(0, reason); >> > qemu_aio_flush(); >> > bdrv_flush_all(); > Why this change? Without it, you could have two threads calling into do_vm_stop and the second would not wait for all CPUs to be paused. Still not perfect as you'd get double notifications, you would need a condition variable or QemuEvent (from the RCU series) for that. Paolo
diff --git a/cpus.c b/cpus.c index de70e02..f35f683 100644 --- a/cpus.c +++ b/cpus.c @@ -122,8 +122,8 @@ static void do_vm_stop(int reason) { if (vm_running) { cpu_disable_ticks(); - vm_running = 0; pause_all_vcpus(); + vm_running = 0; vm_state_notify(0, reason); qemu_aio_flush(); bdrv_flush_all(); @@ -1027,7 +1027,7 @@ void cpu_stop_current(void) void vm_stop(int reason) { - if (!qemu_thread_is_self(&io_thread)) { + if (cpu_single_env) { qemu_system_vmstop_request(reason); /* * FIXME: should not return to device code in case
Currently, when any thread other than iothread calls vm_stop, it is scheduled to be executed later by the iothread. This patch allows the execution of vm_stop from threads other than iothread. This is especially helpful when the migration is moved into a separate thread. Signed-off-by: Umesh Deshpande <udeshpan@redhat.com> --- cpus.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)